A virtual machine (VM) is a software-simulated complete computer system that has complete hardware system functions and runs in a completely isolated environment. By using VM software, a user may simulate one or multiple virtual computers on a physical computer. These virtual computers work like real computers. For example, the user may install an operating system and applications and access network resources on these virtual computers. For the user, the VM is only an application executed on the physical computer. However, for the applications executed on the VM, the VM is like a real computer.
With the increase of server utilization, the investment costs of enterprise servers are required to be lower. Therefore, a technology called server virtualization is developed. Server virtualization means abstracting physical resources of servers as logical resources and changing one server into multiple mutually isolated virtual servers or changing multiple servers into one server. Server virtualization may break the physical limit of resources and change the CPU, memory, magnetic disk, and I/O hardware into a resource pool that can be dynamically managed. The core idea of server virtualization is to simplify management and improve efficiency by prioritizing resources and allocating the resources of servers to loads that need the resources most at any time and at any place, so as to reduce resources reserved for a single load peak.
With the emergence of the VM, especially the server virtualization technology, a running entire VM can be migrated immediately from one server to another server by using the complete virtualization of the server, storage, and network connection. This is known as real-time migration of a VM.
After a server is virtualized, the same physical port of a switch may carry traffic of multiple or even dozens of VMs. However, the switch needs to configure different network policies for different VMs. On the other hand, with the real-time migration of the VM on the server, the network policy on the switch also needs to be migrated.
In the prior art, to configure and migrate a network policy on the switch, a network administrator performs manual configuration on the switch through the management center. The manual configuration features huge workload and poor punctuality, and affects real-time service performance of the VM.